Where can I find a tutorial for making bill of material (3D+2D)
How can you delete a bom that you made in 3D
How can you reset it?
The numbres start counting from 005, 001-004 are not existing
Can somebody help me

There is no specific tutorial on BOM as far as I know.
There is only the Online Help.

The BOM in 3D is associative to the assembly, it cannot be deleted.
It is allway there.
You can only shoose to visualise it in the tree or not (by right click on "Assembly" in the tree)
If you made some changes to the assembly and would like to update the information in the tree, you can rightclick on Assembly, then choose "regenerate".

If you asked to create the indexes automatically in 3D, you can remove them by using the option "Remove indexes = YES" in the same function.
If TS starts counting on 005, are you shure you do not have some "parts" or sub-assemblies in the assembly, but not in the BOM?
Or maybe you gave manually an index when defining the part?